1. Field of the Invention
The present invention relates to information retrieval and, more particularly, to accelerated retrieval of content information over a network.
2. Description of the Related Art
The Internet is a resource for tremendous amounts of content information. As examples, the content information can include text, images or other types of data. A user normally accesses the Internet using a connection provided by a modem and a regular telephone line or ISDN line, or by a T1 line or leased line. The connection to the Internet may be indirectly through an Internet Service Provider (ISP) or more directly to the Internet (or World Wide Web). The higher the bandwidth supported by the connection, the better the responsiveness of the Internet to the user's requests. For example, since a T1 line offers substantially greater bandwidth than does a 28.8 kbps modem and regular telephone line, the connection to the Internet provided by the T1 line will provide substantially faster responsiveness to a user's requests than would the 28.8 kbps modem.
Internet proxy servers have been used to allow multiple users to share Internet access through a common high speed connection. Examples of such Internet proxy servers are (1) WinGate available from Deerfield Communications Company and (2) Microsoft Proxy Server available from Microsoft Corporation. Shared connections facilitate providing firewalls to prevent unauthorized access into the user's (e.g., corporate) internal computers. These shared connections can also provide the Hypertext Transfer Protocol (HTTP) caching to allow improved responsiveness. These Internet proxy servers can also provide site filtering to prevent user (behind the Internet proxy server) access to certain Internet sites.
HTTP caching operates to locally store frequently accessed Internet material so that it becomes quickly available when subsequently requested. HTTP caching is described in the Hypertext Transfer Protocol (HTTP), version 1.1, which is hereby incorporated by reference. Such caching enables an organization to more efficiently share the bandwidth of the Internet connection.
Content negotiation is also known and described in the HTTP, version 1.1. Content negotiation is the process in which a HTTP response to a HTTP request is chosen to be that which is most suitable, assuming of course that there is a choice. The content negotiation can be client-driven or server-driven. The content differences being negotiated can vary widely but are nevertheless stored on a content server on the Internet. As an example, the content differences could be different languages or different size images. In such a case, a client may negotiate on behalf of a user with a content server to receive smaller (e.g., less robust, lower quality, or smaller image area) images instead of commonly provided larger images from the server. If the content server can provide the smaller images, then the user is able to receive and display the information (e.g., images) faster than had their been no choice or no negotiation. Thus, in some cases, the negotiation facilitates improved bandwidth utilization and responsiveness of the Internet.
One problem with the conventional approaches to content delivery over the Internet is that most content servers do not offer multiple versions of information content. As a result, content negotiation, even if available, is not supported by most content servers. There are also no standards on what types of versions or variations of information content a content server should make available. Consequently, content negotiation is difficult to obtain over the Internet.
Another problem is that while caching can improve responsiveness of the Internet to requests, it speeds only subsequent requests for the same information from a shared Internet connection. As a result, there is never any performance improvement for initial requests for information content from the Internet.
Thus, there is a need for improved techniques for rapid and efficient delivery of information content from the Internet to a user.